Improvement in steam-generators



AD. W fa/@mfg ffii/f7? 7717 '/f JWM 554- AM. PHOTO-LITRO. CD. NM (OSBDRNE'S PROCESS) UNITED STATES PATENT OFFICE.

ROBERT V. THOMSON, OF EDINBURGH, GREAT BRITAIN.

Spceication forming part of Letters Patent No. 55,564, dated October 2, 1866.

To all whom it may concern:

Be it known that I, ROBERT WILLIAM THOM- soN, of Edinburgh, in the county of Mid- Lothian, Kingdom of Great Britain and Ireland7 have invented new and useful Improvements in Steam-Boilers; and I declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, and to the reference numerals and letters marked thereon.

My invention relates to improvements more particularlyapplicable to steam-boilers of com paratively small size and of the vertical class; and its object is to render such boilers more eicient,wl1ile retaining simplicity7 in construction with facility for cleaning and repairing.

The improvements consist in constructing steam-boilers of the kind referred to with vertical fire-gas tubes arranged in a circle or circles, and with a vessel projecting down into the furnace from within such circle of tubes, and which is enlarged below its attachment to the tube-plate, so as to compel the fire-gases to pass up round it in a thin iilm.

And in order that my invention may be properly understood by others skilled in the art, I will now proceed to particularly describe the improvements in which it consists, premisin g that they are shown upon the accompanying drawings- Figure l being a vertical section, and Fig. 2 a horizontal section, as taken at the line A A in Fig. l. These figures are drawn to a scale of one inch to the foot. Fig. 3 on the drawings is a vertical section, showing a modification differing slightly from that shown in Figs. 1 and 2.

The same reference-numerals are used to mark the same or like parts .in all the figures.

The external shell, l, is in the common form of a vertical cylinder, but which is made with the enlargement 2 at its upper part in the modification shown in Figs. l and 2. Within and attached to the bottom of the shell l there is an inner shell, 3, of a slightly tapered form, and constituting the sides of an internal furnace, which is supplied with fuel by a door, 4, arranged in the ordinary Way. To the top of the furnace-shell 3 there is riveted a iianged annular top or crown-plate, 5, and a number of tubes, 6, arranged in a circle, have their lower ends fixed in this plate, while their upper ends are iixed in an upper tube-plate, 7. The upper tube-plate 7 is riveted to the bottom of a cylindrical or slightly tapering shell, 8, the upper part of which is riveted to the contracted upper end of the external shell, l.

Within the circle of tubes 6, and in the centrai opening of thelower annular tube-plate, 5, there is riveted a vessel, 9, which is, by preference, made of copper, the other parts of the boiler being of the usual materials. This vessel 9 occupies the upper part of the furnace 3, and is of a spherical or other convenient form, having its horizontal area more or less en larged below its attachment to the tube-plate 5, and it furnishes very efficient heating-surface, the lire-gases in rising toward the tubes 6 being compelled to spread over the bottom of it, and to pass between its sides and the sides ot1 the furnace in a comparatively thin cylindrical sheet, while the contraction of its upper part conveniently affords space for fixing the tubes 6.

Vith this arrangement, while the aggregate annular space between the vessel 9 and the furnace sides 3 is ample for the upward passage of the fire-gases, all parts of these gases are compelled to pass very close to the heating-surfaces, and have thus a better opportu-v nity of giving up their heat than in ordinary arrangement-s. At the same time the vessel 9 is interposed between the tube-plate 5 and the directly radiated heat, and while thus saving the tube-plate, presents in itself the best possible heating-surface.

Access for cleaning the inside of the vessel 9 and the outsides of the tubes 6l is very conveniently obtained by a man-hole, l0, in the upper tube-plate, 7, while access to this manhole l0, and for cleaning the insides of the tubes 6, is obtained by removing the uptake or chimney l1.

In the modification shown in Figs. l and 2, it is intended to keep the water-levelW L above the upper tube-plate, 7, so as to completely cover and protect the' tubes 6 5 and the enlargement 2 in the outer shell is formed in order to give the necessary steam-*space above the tube-plate 7.

A slightly cheaper boiler may, however, be made, so as to possess the principal ativantages ofiny improvements, in the manner shown in' Fig. 3. In this modification the upper tubeplate, 7, simply forms the top of the boiler, the outer shell of which is of uniform, or nearly uniform, diameter from top to bottom, while the water-level TvV L crosses the tubes 6 somewhat below their upper ends.

When the boiler is made somewhat larger than what is shown in the drawings, the regas tubes 6 may be disposed in two concentric crolesinstead of one, as hereinbefore described.

Vhat I claim as my invention, and desire to secure by Letters Patent, is-

The constructing of vertical boilers with ire- EDMUND HUNT, ADoLF SJBERG. 

